Stamping operations are done using a die. The die includes an upper die and a lower die, also referenced herein as a slide press and a die cushion respectively. A sheet of material, also referenced in the art as a blank, is placed between the slide and die cushion and the slide and die cushion are pressed against each other so as to form the blank into a desired part.
The part may then be visually inspected to ensure that no abnormalities existed during stamping operations. As visual inspection may be time consuming and subject to human error, systems have been put in place to make the inspection automated.
For instance, it is known to use the displacement of the press with respect to stamping operations to determine whether or not any flaws occurred during stamping operations. Other methods include measuring compressive and tensile forces on the production part. However, these methods do not take into account the work and force peaks which are transmitted during the stamping operation and thus will not determine the type of the flaw that has occurred. Further, such methods and systems do not provide the type of defect present in the stamped part.
Accordingly, it remains desirable to have a system which not only detects whether or not the part is defective but will also provide the type of flaw that occurred thus allowing for operators and management to reconfigure stamping operations to eliminate the flaw. For example, if it is detected that the machine has produced parts which have wrinkles, then the forming characteristics of the forces with respect to time may direct the user as to where in the forming process the wrinkles have been formed.